[43.13] The Distribution of Disk Stars in Type II Galaxies

About 49% of barred galaxies and 11% of unbarred systems
show inner truncations in their disk surface brightness
profiles. These result from a dearth of inner disk stars
rather than obscuration by dust. Disks of galaxies with
inner truncations have shorter scale lengths and higher
surface brightness parameters. Truncated profiles could
result from a radial redistribution of an inner disk stellar
population, but purely azimuthal or vertical redistributions
cannot give the observed light distributions. Alternatively,
star formation might have been inhibited through tidal
disruption of prestellar clouds. Neither process explains
the systematically different outer disk parameters found for
truncated systems. Resonances associated with disk
kinematics might inhibit gas inflow, thus preventing the
formation of stars in the inner disk.